Loading coil



Avril l 1924:

W` FONDILLER LQADING COIL Filed May 2l 1921 h. N QN Twmwm BMN Rh Amc N s@www Patented Apr. 22, 1924.

narran` llUallES PATENT f FMQE,

WILLIAM FONDILLER, O'F NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOM- P'NY, INCORPORATED, 0F NEW YORK,

N. Y., A CORPORATION OF NEW' YORK.

LOADNG COEL.

Application filed May 21,

T0 al?, fic/2,0m t may con-cern.'

Be it known that l, lNi'LLrAM FoNmLLnn, a citizen ot the United States,residing at New York city, in the county of New York, State of Newliiorlr7 have invented certain new and useful improvements in LoadingCoils, of which the toll-turing is a full, clear, concise, and erectdescription.

This invention relates to inductance devices and more particularly itrelates to a unitary loading device for a duplex circuit.

As is well known in the art, it is frequently desirable to addinductance units at one or more points to a signaling line in order toimprove its transmission characteristics.

An object of this invention is to provide a unitary inductance devicewhich may be inserted in a duplex circuit for simultaneously loading thetwo physical circuits and the derived phantom circuit whereby the use ofan inductance device for each oit these circuits is renderedunnecessary.

One form of the inductance device this invention may have, comprisesfour parallel members with a cross at each end ot the parallel membersfor oining them. The inductance for each wire of each physical circuitcomprises a winding on one of the parallel members and may also comprisesupplementary windings on arms of the crosses, which supplementarywindings may be included in each side circuit in such a manner that theratio between the physical and phantom loading may be made any desiredvalue.

This typeot kinductance device possesses advantages over the toroidaltype of loading coil in that the loading coil or this inventioncomprises only straight portions which may be readily wound without thenecessity of providing special and expensive machinery. lt is preferablethat the magnetic means joining the units of the four parallel membersshould each bein the form of a cross, since it has been found that suchan arrangement tends to eliminate more completely cross talk between theside circuits and the phantom circuit of the three talking circuitsloaded by the device, than it is possible to obtain from magneticjoining means of other types, such as a toroid or a rectangular frame.

r1`his invention will be better understood by reference to the followingdetailed de- 1921. Serial No. 471,316.

scription, taken in connection with the accompanying drawings in whichFig. 1 represents an inductance device according to this invention,arranged to load two physical circuits and the derived phantom circuit,in which non-magnetic gaps are provided in the cross members of the corefor increasing the ratio of phantom to side circuit loading7 and Fig. 2represents a modification of Fig. 1 in which the ratio of phantom toside circuit loading may be adjusted by varying the number of turns ofthe supplementary windings located on the `cross members.

Fig. 1 discloses two two-wire circuits comprising line'conductors 10 and11, and 12 and 13, respectively. 14 and 15 are signaling devices whichmay be employed for transmitting signals such as telephone currents overline conductors 10 and 11 while the signaling devices 16 and 17 arearranged to signal over line conductors 12 and 13. The signaling devices18 and 19, by connections well known in the art, are ar ranged forsignaling over the phantom circuit derived by employing line conductors10 and 11 in parallel for transmission of the signaling currents in onedirection and line conductors 12 and 13 in parallel for the transmissionof the signaling currents in the opposite direction.

The inductance device disclosed in Fig. 1 tor simultaneously loading thephysical circuits and the derived phantom circuit comprises tourparallel members 20, 21, 2:2 and i QS which are at one end joined by across comprising the four arms 24, 25, 26 and 2? and are joined at `theother end by a cross comprising the four arms 28, 29, SO and 31. Lineconductor 1() is loaded by the main inductance winding 32 on core memberQ1 and by the two supplementary windings and 34 on the cross arms 8O and26. Line conductor 11 is loaded by the main inductance winding on coremember 22 and by the supplementary windings 36 and 37 located on thecross arms 29 and 25. Similarly line conductor 12 is loaded by the maininductance winding 38 and supplementary windings 39 and 420; and lineconductor 13 is loaded by main inductance winding l1 and thesupplementary windings 412 and 43.

It' we assume that the instantaneous physical current in the twov sidecircuits is in the direction of the full arrows adjacent the lineconductors, the direction of the flux produced in the core members isshown by the full line arrows on each core member. Similarly,instantaneous current in the phantom circuit in the direction indicatedby the dotted arrowsJ will produce a flux in the loading coil in adirection indicated by the dotted arrows on the core members. As shownby these arrows, the ilux for side circuit 10, 11 starting tor examplein .core member A:a3 passes through arms and 24, parallel member20,\cross arms 28 and 31, back to parallel member 23, and the directionsof the flux for the'two'main windings and the four supplementarywindings are all in the same direction. Similarly, the flux for the sideCircuit 12, 13, starting for example in parallel member 22 traversescross arms 26 and 25, parallel member 21y cross arms 29 and 30, back toparallel member 22; and the directions of the Hur: iiorthe two main.windings and the four supplementary windings surrounding the describedrectangle are all in the same direction. A portion of 'the phan- 'tomcircuit flux 'traverses parallel member 23 of side circuit 12, 13,cross. arms 27 and 25, parallel member 21 of side circuit 10, 11, crossarms 29 and 31, back to parallel member 23; and another portion of thephantom circuit iiuX traverses core member 20 of side circuit 12, 13,cross arms 24, 26, parallel member 22 of iside, circuit 10, 11, crossarms 30 and 287 back to parallel member 20. lf desired,non-magnetic gaps45 and 46 may be provided in the cross arms arranged in such a manner asto oder high reluctance to the side circuitfluX and but littlereluctance to the phantom circuit flux. These nonmagnetic gapsA Vas iswell known in the art and as described and claimed in my PatentNo.1,253,365 of January 15, 1918, serve to increase the ratio of phantomto side circuit loading, this ratio increasing with an increase in thewidth ofn thenon-magnetic gap. inasmuch as the iiuXes of thesupplementary windings are arranged in this figure to aid the mainwindings for side circuit currents and oppose tor phantom circuitcurrents, it follows that after the ratio of side to phantom loading hasbeen determined roughly by the width of the non-magnetic gaps for givenmain and supplementary windings,-tlie number of turns of thesupplementary windings may be varied to accurately determine this ratio.From the above description of the direction of the flux in each of themain windings and the supplementary windings, it will be evident tothose skilled in the art that the flux for each of the three talkingcircuits is arranged in such a manner that cross talk therebetween isminimized.

Fig. 2, discloses a modification oi Fig. 1 in which the ratio of phantomto side circuit loading `may be increased to any desired lfor phantomcurrents but oppose them for side circuit currents. lt is thereforeevident that inereasingthe number of turns o'f the supplementarywindings with regard to its main inductance winding will increase theratio vof phantom to side circuit loading while decreasing the number ofturns of the supplementary windings will decrease ythis ratio. inasmuchas Fig. 2, `is similar to Fig. 1y except that the non-magnetic gaps 45and 46 have been omitted, and the direction of the winding of each ofthe supplementary windings has been reversed in each case, it is notbelieved necessary to describe F ig. 2in detail. Corresponding parts ofthe two figures have therefore been given similar reference numeralsexcept that the numerals for Fig. 2 are designated -as 10 11', etc.

It is to be understood that this invention is not limited to the use ofwindings on both the parallel members and theV crossarms, since Athewindings on either the parallel members or the cross arms, may beomitted, if desired, It is also to be understood that the structuredescribed above may be variously modified without departing in 'any wisefrom the spiritV of this invention, as defined in the appended claims.

l/Vhat is claimed is:

1. An inductance Vdevice having a core comprising twoco-a-Xialrectangular frames at right angles to each other, the longitudinal sidesof said rectangles being separable from the radial sides andaninductance winding on each side of each rectangle.

2. An inductance device having acore composed of two crosses, fourseparable arms joining the ends of said crosses, and windings placed ona plurality of the sides of said core. Y 1 [f 3. A loading coil for aplurality of physical circuits and a derived phantom circuit comprisinga core comprising four parallel members and a cross at each end of saidmembers, each ofl said crosses having an arm resting on the end ol onelof said members and a winding on each of said members for one of saidphysical circuits;

4. A loading coil for a plurality of physical circuits and a derivedphantom circuit comprising a core comprising a plurality of parallelmembers, and means at eachend of said members for joining saidvmembers,a winding on each of said parallel members for one of. said circuits,and a plurality of windings on said means, one of said windings on oneof said meansbeing connected to one of said windings on one of saidparallel members. u F

VA loading coil for two physical twowire circuits and the derivedphantom circuit having a core comprising four parallel members, a crossat each end of said members for joining said members, a main wnding oneach of said parallel members for one of said wires, and a supplementarywinding i on each arm of each cross.

6. A loading coil for two physical circuits and th'e derived phantomcircuit having a core comprising four parallel members,y a cross at eachend of said members for lioining said members, a main winding on each ofsaid parallel members for one of the wires of said circuits, and asupplementary winding on each arm of one of said crosses for one of thewires of said circuits,the main winding on each. parallel member beingdirectly connected to a supplementary winding on an arm. of said crossadjacent another of said parallel members.

7. A loading coil for two physical circuits and the derived phantomcircuit having a core comprising four parallel members, a cross at eachend of said members for joining said members, a main winding on each ofsaid parallel members for one of the wires of said circuits, and asupplementary winding on each arm of one of said crosses for one of thewires of said circuits, the main winding on each parallel member beingdirectly connected to a supplementary winding on an arm of said erossadjacent another of said parallel members, said supplementary windingsbeing wound in such a direction as to aid the main windings for phantomcircuit currents opposing said main windings for side circuit currents.

ln witness whereof, l hereunto subscribe my name this l9th day oi Nay,A. D. 1921.

WLLIAM FQNDILLER.

